Im a little late to the party but went overkill on the CPU but glad you fixed the PSU. Your really need to play with your OC settings and you will be able to get much better hashrates. I would try even up to +150 core +600 memory and see if its stable at 70% if you got Samsung memory in your GPUs it might be possible.
OK. Will try with more OC. So far it's all stable. GPU temp is around 68-73C per card.
my rigs have also the fans not on auto. i was playing around with each gpu to keep em under 70c